In recent years, small and thin electronic equipment has been demanded and thus semiconductor devices have been requested to have bare semiconductor chips directly mounted on circuit boards (bare chip mounting). Particularly, semiconductor devices have been demanded in which the circuit surfaces of semiconductor chips are opposed to circuit boards (flip-chip mounting).
In a flip-chip semiconductor device of the related art, as shown in FIG. 45, a semiconductor chip 51 having internal connection terminals such as metal bump electrodes is mounted on a circuit board 50 by flip-chip connection. Reference numeral 52 denotes an anisotropic conductive adhesive.
In this semiconductor device, an external force applied to the semiconductor chip 51 may damage the anisotropic conductive adhesive 52, causing faulty electrical connection between the circuit board 50 and the semiconductor chip 51.
In Patent Literature 1, as shown in FIG. 46, surface unevenness 53 is formed on a portion (fillet) of the anisotropic conductive adhesive 52 protruding from the outer circumference of the semiconductor chip 51. Thus it is possible to improve the mechanical strength of the anisotropic conductive adhesive 52 and reduce the occurrence of faulty electrical connection between the circuit board 50 and the semiconductor chip 51.
In Patent Literature 2, in order to increase a radiating area in the resin molding of circuit components, a plurality of holes are formed by a jet of air on the surface of a molding resin covering the circuit components.